Moving picture recording and sending device

ABSTRACT

A subject of the invention is to mix video signals of plural channels in time division and record these video signals to a recording medium, and select and transmit the video signal of a specific channel to a terminal device of a remote place. Therefore, the invention has a video signal switching unit for mixing the video signals of the plural channels in time division; a first video signal compressing unit for compressing the mixed video signals from the video signal switching unit; a unit for recording the video signal compressed by the first video signal compressing unit to the recording medium; second video signal compressing units for selecting a channel from the mixed video signals and compressing the video signals in a compressibility higher than that of the first video signal compressing unit; and a unit for transmitting the video signal compressed by the second video signal compressing unit. The video signal of a specific channel among the mixed video signals of the plural channels can be transmitted to a remote place by the above construction.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a video signal recording and transmitting device for compressing video signals of plural channels mixed in time division, and recording the video signals to a recording medium, and compressing the video signals in different compressibilities and transmitting these video signals to an external device.

[0002] A monitoring system for recording a video signal photographed by a camera in a monitoring place to the recording medium, and further transmitting the video signal to the monitoring device of a remote place via a communication network, etc. is devised. In such a monitoring system, it is necessary that the video signal recorded to the recording medium is a video signal high in resolution and time resolution. However, it is necessary to transmit the video signal transmitted to the monitoring device of the remote place by reducing the resolution and the time resolution in accordance with the limit of transmission capacity of the communication network. In a technique with respect to the conventional monitoring system, the photographed video signal is compressed in plural modes having different compressibilities, and low compression data are recorded to the recording medium, and high compression data are transmitted. For example, see JP-A-2000-59758.

SUMMARY OF THE INVENTION

[0003] In the above conventional technique, the video signal photographed by a single camera or plural cameras is recorded, and is monitored by transmitting the video signal to the monitoring device arranged in the remote place. However, when plural cameras are arranged and the video signal is recorded by using one recorder, it is general to use a system for mixing the video signals of plural channels in time division and recording the video signals to the recording medium. In such a system, the video signals of the plural channels are mixed in time division and are transmitted, and the video signal of a predetermined desirable channel is selected and monitored by the monitoring device to perform the monitoring operation by the monitoring device arranged in the remote place. Accordingly, in such a system, it is necessary to have a function for transmitting a video signal except for the video signal required between the image pickup recorder side and the monitoring device side, and selecting the video signal of the predetermined desirable channel in the monitoring device.

[0004] An object of the present invention is to provide a video signal recording transmitter, a monitoring device and a monitoring system for recording the video signals of plural channels to the recorder in time division, and transferring only a video signal required in the monitoring operation between the recorder and the monitoring device.

[0005] To solve the above problems, the present invention is constructed by video signal switching means for mixing video signals of plural channels in time division; first video signal compressing means for compressing the mixed video signals from the video signal switching means; means for recording the video signal compressed by the first video signal compressing means to the recording medium; second video signal compressing means for selecting a channel from the mixed video signals and compressing the video signals in a compressibility higher than that of the first video signal compressing means; and communication means for transmitting the video signal compressed by the second video signal compressing means. The video signal of a specific channel among the video signals of the plural channels can be transmitted to the monitoring device of a remote place by such a construction.

BRIEF DESCRIPTION OF THE DRAWING

[0006] These and other features, objects and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings wherein:

[0007]FIG. 1 is a block diagram showing a first embodiment mode of a remote monitoring system in the present invention;

[0008]FIG. 2 is a block diagram showing a second embodiment mode of the remote monitoring system in the present invention;

[0009]FIG. 3 is a block diagram showing a third embodiment mode of the remote monitoring system in the present invention;

[0010]FIG. 4 is a block diagram showing a fourth embodiment mode of the remote monitoring system in the present invention; and

[0011]FIG. 5 is a block diagram showing a fifth embodiment mode of the remote monitoring system in the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0012] A first embodiment mode of a monitoring system in the present invention will be explained by using FIG. 1. FIG. 1 is a block diagram showing the first embodiment mode of the monitoring system in the present invention. The monitoring system is constructed by a video signal recording transmitter 1, a communication network 3 and a monitoring device (terminal device) 5 arranged in a remote place. The video signal recording transmitter 1 is constructed by video signal input terminals T1-1, T1-2, T1-n for inputting video signals picked up by plural cameras C1-1, C1-2, C1-n thereto, a video signal switch 11 for selecting one of the video signals of plural channels and outputting the selected video signal as a time division signal, a channel switching circuit 12 for outputting a channel selecting signal in the video signal switch 11, an MPEG2 encoder 13 as a first video signal compressing means, a recording medium interface 14, a recording medium 15 such as a hard disc, etc., a zoom processing circuit 16, an MPEG4 encoder 17 as a second video signal compressing means, a conformity circuit 18 and a communication interface 29. The video signal recording transmitter 1 and the monitoring device 5 are connected to each other through the communication network 3.

[0013] The plural cameras C1-1, C1-2, C1-n are means for respectively outputting the photographed video signals to the video signal input terminals T1-1, T1-2, T1-n.

[0014] The video signal switch 11 is a means for sequentially selecting the video signals of the plural channels inputted from the video signal input terminals T1-1, T1-2, T1-n, and mixing the video signals in time division and outputting the video signals to the MPEG2 encoder 13, and also outputting the video signals to the MPEG4 encoder 17 via the zoom processing circuit 16.

[0015] The channel switching circuit 12 is a means for controlling the operation of the video signal switch 11 so as to switch the video signals of the plural channels in e.g., a frame unit. Further, the channel switching circuit 12 outputs the channel selecting signal to the conformity circuit 18.

[0016] The MPEG2 encoder 13 is a first video signal compressing means for performing compression-encoding processing in a first compressibility with respect to the inputted video signal, and setting this video signal to a compression video signal.

[0017] The recording medium interface 14 is a means for performing writing processing of the compression video signal to the recording medium 15. Further, the recording medium interface 14 is also a means for performing reading processing of the compression video signal recorded to the recording medium 15.

[0018] For example, the recording medium 15 is constructed by a hard disc, a DVD and other memories, and is a means for storing the compression video signal, etc. The recording medium 15 itself can be constructed so as to be freely detached from the video signal recording transmitter 1.

[0019] The zoom processing circuit 16 is a circuit for performing zoom processing for cutting and enlarging an arbitrary portion in a frame image of the inputted video signal and converting resolution on the basis of a zoom processing assigning signal received from the monitoring device 5 through the communication interface 29.

[0020] The MPEG4 encoder 17 is a second video signal compressing means for performing compression-encoding processing in a second compressibility with respect to the compression video signal of a channel assigned by the channel assigning signal received from the monitoring device 5 through the communication interface 29, and setting this encoded compression video signal to a compression video signal. Information used in the compression-encoding processing in the MPEG2 encoder 13, e.g., a moving vector (MV) can be used as information used in this compression-encoding processing. Thus, it is possible to reduce the processing amount of the compression-encoding processing in the MPEG4 encoder.

[0021] The conformity circuit 18 is a means for comparing the channel assigning signal received from the monitoring device 5 through the communication interface 29 and the channel selecting signal from the channel switching circuit 12, and judging whether both the channel assigning signal and the channel selecting signal are conformed to each other or not. When the channel assigning signal and the channel selecting signal are conformed to each other, the compression-encoding processing in the MPEG4 encoder 17 is performed.

[0022] The communication interface 29 is an interface having an action for transmitting the compression video signal compressed in a high degree in the MPEG4 encoder 17 to the monitoring device 5 through the communication network 3, and receiving a signal such as the channel assigning signal, a zoom processing assigning signal, etc. from the monitoring device 5 through the communication network 3.

[0023] The communication network 3 is a communication network for connecting the video signal recording transmitter 1 and the monitoring device 5, and transmitting a signal such as the compression video signal, the channel assigning signal, the zoom processing assigning signal, etc. between both the video signal recording transmitter 1 and the monitoring device 5.

[0024] The monitoring device 5 has a function for extending and decoding the compression video signal received from the video signal recording transmitter 1, and displaying the compression video signal on the display screen. The monitoring device 5 also has a function for transmitting a signal such as the channel assigning signal for assigning a channel for receiving the transmitted signal, the zoom processing assigning signal for assigning a zoom processing condition as conditions of a cutting area of the image, enlargement processing resolution conversion processing, etc., and others to the video signal recording transmitter 1.

[0025] In FIG. 1, the plural cameras C1-1, C1-2, C1-n respectively output the photographed video signals to the video signal input terminals T1-1, T1-2, T1-n. The video signals of the plural channels inputted from the video signal input terminals T1-1, T1-2, T1-n are guided to the video signal switch 11. The channel switching circuit 12 outputs the channel selecting signal so as to switch the video signals of the plural channels in e.g., a frame unit, and controls the operation of the video signal switch 11. Accordingly, in the output of the video signal switch 11, the video signals of the plural channels switched in e.g., the frame unit are mixed in time division. The output signal from the video signal switch 11 is guided to the MPEG2 encoder 13, and is also guided to the MPEG4 encoder 17 through the zoom processing circuit 16.

[0026] The video signal inputted to the MPEG2 encoder 13 is compressed and encoded in an MPEG2 format every channel, and is recorded to the recording medium 15 as a compression video signal through the recording medium interface 14.

[0027] In contrast to this, the compression video signal of an assigned channel compressed and encoded by the MPEG4 encoder 17 in an MPEG4 format having a compressibility higher than that of the MPEG2 format is guided to the communication interface 29, and is transmitted to the monitoring device 5 of a remote place via the communication network 3.

[0028] The channel assigning signal received by the communication interface 29 from the monitoring device 5 via the communication network 3 is guided to the conformity circuit 18 and is compared with the channel selecting signal from the channel switching circuit 12. When both the channel assigning signal and the channel selecting signal are conformed to each other, the MPEG4 encoder 17 compresses and encodes the inputted video signal, and outputs this compression-encoded video signal as a compression video signal.

[0029] In this embodiment mode, the video signals photographed by the plural cameras C1 and mixed in time division are compressed and encoded and are recorded to the recording medium 15 by the above operation. Further, the compression video signal compressed in a high compressibility can be transmitted to the monitoring device 5 of the remote place via the communication network 3. The channel of the compression video signal transmitted to the monitoring device 5 of the remote place can be assigned from the monitoring device 5 of the remote place. Accordingly, a predetermined desirable camera screen image among the plural camera screen images can be selected and monitored in the monitoring device 5 of the remote place. Further, in accordance with this embodiment mode, an enlarged image can be received and a required portion within the monitor screen can be enlarged and monitored by giving instructions so as to enlarge the required portion in the image of a predetermined channel to a required size while the images of plural selected channels are sequentially monitored in the monitoring device 5.

[0030] A second embodiment mode of the monitoring system in the present invention will next be explained by using FIG. 2. FIG. 2 is a block diagram showing the second embodiment mode in the present invention. The monitoring system in this embodiment mode is characterized in that a channel selecting mode switching circuit 19 i a channel selecting mode change-over switch 20, a user channel selecting circuit 21 and an automatic channel selecting circuit 22 are added to the video signal recording transmitter 1 shown in FIG. 1. The same portions as the first embodiment mode in the other portions are designated by the same reference numerals as FIG. 1, and the explanations of operations of these portions are omitted.

[0031] The channel selecting mode switching circuit 19 is a circuit for performing switching control so as to select and output one of a channel assigning signal received from the monitoring device 5, a channel assigning signal outputted from the user channel selecting circuit 21, and a channel assigning signal outputted from the automatic channel selecting circuit 22 on the basis of a channel selecting mode assigning signal transmitted from the monitoring device 5 of a remote place and received via the communication network 3. When the channel selecting mode switching circuit 19 receives the channel assigning signal transmitted in the remote place, the channel selecting mode switching circuit 19 is operated so as to treat the received channel assigning signal prior to the other two channel selecting signals.

[0032] The channel selecting mode change-over switch 20 is a means for selectively switching and outputting the inputted, channel assigning signal by instructions from the channel selecting mode switching circuit 19.

[0033] The user channel selecting circuit 21 is a circuit for assigning a channel transmitted to the monitoring device 5 of the remote place by a user of this video signal recording transmitter in its arranging place, and outputs the channel assigning signal corresponding to the channel set by the user.

[0034] The automatic channel selecting circuit 22 is a circuit for automatically switching and selecting the channel of the video signal transmitted to the monitoring device 5 of the remote place. The automatic channel selecting circuit 22 outputs the corresponding channel assigning signal so as to sequentially switch the channel of the video signal at a predetermined time interval, e.g., an interval of several seconds.

[0035] The first embodiment mode already described is constructed such that the channel of the video signal compressed and encoded by the MPEG4 encoder 17 and transmitted by the communication interface 29 is assigned from the external monitoring device 5 via the communication network 3. However, in the second embodiment mode, another channel assigning method can be also performed.

[0036] In this embodiment mode, while the video signals of all the channels are normally sequentially switched by the above operation at an interval of e.g., several seconds, the video signals are transmitted to the monitoring device 5 of the remote place (in an automatic channel selecting mode), or the video signal of a specific fixed channel assigned by the user of the video signal recording transmitter side is transmitted to the monitoring device 5 of the remote place (in a user channel selecting mode). When there is a channel assignment from the monitoring device 5 of the remote place, the video signal of the assigned channel can be transmitted to the monitoring device 5 of the remote place (in a monitoring device channel selecting mode).

[0037] A third embodiment mode of the monitoring system in the present invention will next be explained by using FIG. 3. FIG. 3 is a block diagram showing the third embodiment mode of the monitoring system in the present invention. This embodiment mode is characterized in that a channel code adding circuit 23, a timing adjusting circuit 24, an MPEG2 decoder 25, an input selecting switch 26-1, a channel signal selecting switch 26-2, a regenerating channel discriminating circuit 27, a transmitting signal switching circuit 28 and a video signal output terminal T2 are added to the video signal recording transmitter 1 in the first embodiment mode shown in FIG. 1. The same portions as the first embodiment mode in the other portions are designated by the same reference numerals as FIG. 1, and the explanations of operations of these portions are omitted.

[0038] Namely, the third embodiment mode is constructed such that a regenerating function of the recording medium 15 is provided and a required channel video signal can be received as a compression video signal from the video signal recording transmitter 1 by operating the recording medium 15 by the monitoring device 5 in addition to the first embodiment mode.

[0039] The channel code adding circuit 23 is a circuit for adding a channel code showing the channel of the video signal selected by the channel switching circuit 12 to the compression video signal compressed and encoded by the MPEG2 encoder 13.

[0040] The timing adjusting circuit 24 is a delay circuit corresponding to a time required to perform the compression-encoding processing of the video signal in the MPEG2 encoder 13. This timing adjusting circuit 24 is a circuit for inputting the channel selecting signal from the channel switching circuit 12 to the channel code adding circuit 23 by conforming timings of the compression video signal processed in the MPEG2 encoder 13 and the channel code to each other.

[0041] The MPEG2 decoder 25 is a circuit for extending and decoding the compression video signal of an MPEG2 format read from the recording medium 15 via the recording medium interface 14 to the original video signal, and setting the compression video signal to a decoded video signal. The decoded video signal is outputted to the MPEG4 encoder 17 and the regenerating channel discriminating circuit 27 through the video signal output terminal T2, the input selecting switch 26-1 and the zoom processing circuit 16.

[0042] The input selecting switch 26-1 is a circuit for selecting one of the video signal from the video signal switch 11 and the video signal regenerated from the recording medium 15 and extended and decoded by the MPEG2 decoder on the basis of a transmitting signal switching signal from the transmitting signal switching circuit 28, and outputting the selected video signal to the zoom processing circuit 16.

[0043] The channel signal selecting switch 26-2 is a circuit for selecting one of the channel selecting signal from the channel switching circuit 12 and the channel code added to the compression video signal regenerated from the recording medium 15 and discriminated in the regenerating channel discriminating circuit 27 on the basis of the transmitting signal switching signal from the transmitting signal switching circuit 28. The selected channel selecting signal or channel code is outputted to the conformity circuit 18.

[0044] The regenerating channel discriminating circuit 27 is a circuit for reading the channel code added to a regenerating compression video signal read from the recording medium 15, and discriminating the channel during the regeneration, and outputting the channel code. The channel code is outputted to the conformity circuit 18 through the channel signal selecting switch 26-2.

[0045] The transmitting signal switching circuit 28 is a circuit for giving instructions for selecting one of the video signal picked up by a camera, and the video signal obtained by regenerating, extending and decoding the video signal once recorded to the recording medium 15. The transmitting signal switching circuit 28 outputs the transmitting signal switching signal on the basis of a transmitting signal selecting signal received from the monitoring device 5.

[0046] The video signal output terminal T2 is a terminal for outputting the video signal obtained by extending and decoding the compression video signal recorded to the recording medium 15.

[0047] The monitoring device 5 of a remote place outputs the transmitting signal selecting signal and a regenerating control signal for controlling whether the video signal is regenerated in which position of the recording medium 15 to the communication interface 29 via the communication network 3. The transmitting signal selecting signal shows whether the video signal in real time photographed by the camera is transmitted to the monitoring device 5 of the remote place, or the past video signal regenerated from the recording medium 15 is transmitted to the monitoring device 5 of the remote place.

[0048] The communication interface 29 outputs the received transmitting signal selecting signal to the transmitting signal switching circuit 28. The transmitting signal switching circuit 28 controls the operations of the input selecting switch 26-1 and the channel signal selecting switch 26-2 in accordance with this transmitting signal selecting signal. The communication interface 29 also outputs the received regenerating control signal to the recording medium interface 14. The recording medium interface 14 controls a regenerating operation of the recording medium 15 in accordance with this regenerating control signal.

[0049] At a recording time, the channel selecting signal from the channel switching circuit 12 is inputted to the channel code adding circuit 23 through the timing adjusting circuit 24. The channel code adding circuit 23 adds the channel code showing the channel of the video signal selected by the channel switching circuit 12 to the compression video signal compressed and encoded by the MPEG2 encoder 13. The compression video signal adding the channel code thereto is recorded to the recording medium 15 through the recording medium interface 14.

[0050] In contrast to this, at a regenerating time, the compression video signal regenerated from the recording medium 15 is inputted to the MPEG2 decoder 25 through the recording medium interface 14. The MPEG2 decoder 25 extends and decodes the inputted compression video signal of the MPEG2 format to the original video signal, and outputs this original video signal to the video signal output terminal T2, and outputs this original video signal to the MPEG4 encoder 17 through the input selecting switch 26-1 and the zoom processing circuit 16.

[0051] The compression video signal adding the channel code regenerated from the recording medium 15 thereto is inputted to the regenerating channel discriminating circuit 27 through the recording medium interface 14. The regenerating channel discriminating circuit 27 reads the channel code added to the inputted compression video signal, and discriminates the channel during the regeneration, and outputs this channel to the conformity circuit 18 through the channel signal selecting switch 26-2.

[0052] Similar to the first embodiment mode, the operation of the MPEG4 encoder 17 is next controlled so as to perform the compression-encoding processing when the discriminated regenerating channel and the channel assigned by the monitoring device 5 of the remote place are conformed to each other.

[0053] In this embodiment mode, it is possible to select which of the video signal of real time photographed by the camera and the past video signal regenerated from the recording medium 15 is sent to the monitoring device 5 of the remote place by the above operation from the monitoring device 5 of the remote place. Further, it is possible to select whether the video signal in which position of the recording medium is regenerated and which channel of the regenerated video signal is transmitted to the monitoring device 5 of the remote place, from the monitoring device 5 of the remote place.

[0054] A fourth embodiment mode of the monitoring system in the present invention will next be explained by using FIG. 4. FIG. 4 is a block diagram showing the fourth embodiment mode of the monitoring system in the present invention. This embodiment mode shows a system in which a signal from a monitoring camera CI inputted to the video signal recording transmitter 1 in the second embodiment mode shown in FIG. 2 is set to a signal obtained by the MPEG2 compression processing. In this embodiment mode, a camera device C1 is constructed such that this camera device C1 has a lens C11, an image sensor C12, an MPEG2 encoder C13 and a LAN interface C14. Plural camera devices C1-1, C1-2, C1-n are respectively connected to the video signal recording transmitter 1 through a local area network (LAN) 7.

[0055] The video signal recording transmitter 1 is characterized in that the video signal switch 11 in the video signal recording transmitter 1 shown in FIG. 2, the channel switching circuit 12 for outputting the channel selecting signal in the video signal switch 11, and the MPEG2 encoder 13 as a first video signal compressing means are omitted, and an MPEG2 decoder 25 and a video signal output terminal T2 are added. The same portions as the first, second and third embodiment modes in the other portions are designated by the same reference numerals as FIGS. 1, 2 and 3, and the explanations of operations of these portions are omitted.

[0056] Namely, in the fourth embodiment mode, in addition to the second embodiment mode, the MPEG2 encoder C13 and the LAN interface C14 are arranged within the camera device C1, and the MPEG2 decoder 25 and an assigning channel extracting circuit 111 are arranged in the video signal recording transmitter 1, and the video signal of an assigning channel from the camera device C1 is decoded and extended and can be outputted from the output terminal T2.

[0057] The camera devices C1-1 to C1-n are respectively arranged in separated places, and are connected to each other by the LAN. In each of the camera devices C1-1 to C1-n, the video signal picked up through the lens C11 and the image sensor C12 such as a CCD sensor, etc. is compressed and encoded in the MPEG2 format by the MPEG2 encoder C13 and is changed to a packet, and is then recorded to the recording medium 15 of the video signal recording transmitter 1 through the LAN interface C14 via the LAN 7. The video signal from each of the camera devices C1-1 to C1-n is recorded to the recording medium 15 in time division.

[0058] The assigning channel extracting circuit 111 selects only the packet of an assigned channel among the packets of the MPEG2 format sent from the camera device C1 via the LAN 7, and sends this packet to the MPEG2 decoder 25, and decodes this packet. After a predetermined portion of the image is selected and is enlarged and processed in the zoom processing circuit 16, the predetermined portion is compressed in the MPEG4 format in the MPEG4 encoder 17, and is transmitted to the monitoring device 5 of the remote place through the communication interface 29 via the communication network 3.

[0059] The video signal regenerated from the recording medium 15 and compressed in the MPEG2 format is sent to the assigning channel extracting circuit 111. Only the packet of the assigned channel is then selected among the regenerated packets of the MPEG2 format. Similar to the recording time, the selected packet is next sent to the monitoring device 5 via the communication network 3.

[0060] In this embodiment mode, the video signal obtained by performing zoom processing with respect to the image obtained by selecting a predetermined camera or channel from screen images from the plural cameras or the video signals of plural channels regenerated from the recording medium can be sent to the monitoring device 5 of the remote place by the above operation.

[0061] A fifth embodiment mode of the monitoring system in the present invention will next be explained by using FIG. 4. FIG. 5 is a block diagram showing the fifth embodiment mode of the monitoring system in the present invention. This embodiment mode is characterized in that a zoom processing circuit 15 and an MPEG4 encoder C17 are further arranged in the monitor camera CI connected to the video signal recording transmitter 1 in the fourth embodiment mode shown in FIG. 4, and the zoom processing circuit 16 and the MPEG4 encoder 17 are removed from the video signal recording transmitter 1. The same portions as the fourth mode in the other portions are designated by the same reference numerals as FIG. 4, and the explanations of operations of these portions are omitted.

[0062] Namely, this embodiment mode is characterized in that an MPEG4 encoder function and a zoom processing function are provided in the camera device C1. The camera devices C1-1, C1-2, C1-n are respectively arranged in separated places, and are connected to each other by the LAN 7. In each of the camera devices C1-1, C1-2, C1-n, similar to the fourth embodiment mode, the video signal picked up through the lens C11 and the image sensor C12 is compressed and encoded in the MPEG2 format in the MPEG2 encoder C13, and is changed to a packet. Thereafter, the video signal is recorded to the recording medium 15 of the video signal recording transmitter 1 through the LAN interface C14 via the LAN 7. The video signal from each of the camera devices C1-1, C1-2, C1-n is recorded in time division.

[0063] The camera devices C1-1 to C1-n of this embodiment mode have a function for performing zoom processing with respect to, the picked-up video signal in the zoom processing circuit C16 in accordance with a zoom processing assigning signal received from the monitoring device 5 via the LAN 7, and then compressing and encoding the video signal in the MPEG4 format in the MPEG4 encoder C17, and sending the encoded signal to the LAN 7 through the LAN interface C14.

[0064] A monitoring person of the monitoring device 5 of the remote place assigns the channel of a camera device desirous to perform the zoom processing from the monitoring device 5 while the monitoring person sequentially monitors the video signal sent from the video signal recording transmitter 1. The zoom processing assigning signal transmitted from the monitoring device 5 is received by the communication interface 29 of the video signal recording transmitter 1 via the communication network 3 in accordance with this assignment of the monitoring person, and is sent to the zoom processing circuit C16 through the LAN interface C14 of the assigned camera device C1 via the LAN 7.

[0065] The assigned camera device C1 performs the zoom processing of a predetermined portion of the video signal picked-up in accordance with this zoom processing assigning signal, and then compresses and encodes the predetermined portion in the MPEG4 format, and outputs the encoded portion to the LAN interface C14.

[0066] In this embodiment mode, a signal obtained by selecting a camera and performing the zoom processing from the video signals from the plural camera devices can be sent to the monitoring device of the remote place by the above operation.

[0067] In the first, second and third embodiment modes of the present invention, the transmitted video signal is compressed and encoded in the MPEG4 format, but the output of the MPEG2 encoder 13 may be also converted to the MPEG4 format. In this case, a converting means from the MPEG2 format to the MPEG4 format is arranged instead of the MPEG4 decoder 17. When the video signal of real time photographed by a camera is transmitted to the monitoring device 5 of the remote place, the output of the MPEG2 encoder 13 is converted to the MPEG4 format. When the past video signal recorded to the recording medium 15 is transmitted to the monitoring device 5 of the remote place, a regenerated video signal from the recording medium interface 14 is converted to the MPEG4 format.

[0068] Further, in the first, second and third embodiment modes of the present invention, the compression system is set to the MPEG2 format and the MPEG4 format. However, another compression system may be also used if the compressibility of the video signal transmitted to the monitoring device 5 of the remote place is higher than the compressibility of the video signal recorded to the recording medium 15, and is in conformity with the limit of transmission capacity of the communication network 3.

[0069] In accordance with the present invention, the video signals photographed by plural cameras and mixed in time division are compressed and recorded to the recording medium. Further, the video signal compressed in a high compressibility can be transmitted to the monitoring device of the remote place via the communication network, and the channel of the video signal transmitted to the monitoring device of the remote place can be assigned from the monitoring device of the remote place. Accordingly, a predetermined desirable camera screen image among the plural camera screen images can be selected and monitored in the monitoring device of the remote place.

[0070] While we have shown and described several embodiments in accordance with our invention, it should be understood that disclosed embodiments are susceptible of changes and modifications without departing from the scope of the invention. Therefor, we do not intend to be bound by the details shown and described herein but intend to cover all such changes and modifications a fall within the ambit of the appended claims. 

We claim:
 1. A video signal recording transmitter comprising: an input unit for inputting video signals of plural channels; a video signal input switching unit for switching and outputting the video signal inputs of said plural channels in time division; a first video signal compressing unit for compressing an output from the video signal input switching unit; a recording unit for recording an output signal from the first video signal compressing unit to a recording medium; a second video signal compressing unit for compressing the output from said video signal input switching unit in a high compressibility in comparison with said first video signal compressing unit; a communication unit for transmitting an output signal from the second video signal compressing unit to another device; and a channel selecting control unit for controlling the operation of said second video signal compressing unit so as to selectively compress a specific channel included in the output from said video signal input switching unit.
 2. The video signal recording transmitter according to claim 1, further comprising: a regenerating unit for regenerating the compressing signal recorded to the recording medium; a video signal extending unit for extending the compressing signal regenerated from the regenerating unit; and a transmitting signal selecting unit for switching the extended video signal from the video signal extending unit and the video signal from said video signal input switching unit, and outputting these video signals to said second video signal compressing unit.
 3. The video signal recording transmitter according to claim 2, further comprising: a unit for recording a channel discriminating signal showing which channel of the video signal inputs of said plural channels said video signal input switching unit outputs to the recording medium together with the video signal compressed by said first video signal compressing unit; and a channel discriminating unit for discriminating which channel said regenerating unit regenerates from said channel discriminating signal recorded to the recording medium; wherein said channel selecting control unit is constructed so as to selectively compress the specific channel on the basis of the output from said channel discriminating unit when said transmitting signal selecting unit selects the output from said video signal extending unit.
 4. The video signal recording transmitter according to claim 1, wherein the second video signal is compressed by using information required to compress the first video signal.
 5. The video signal recording transmitter according to claim 1, wherein the video signal recording transmitter has a communication unit for receiving a channel assigning signal from another device, and said channel selecting control unit controls the operation of said second video signal compressing unit so as to selectively compress the specific channel assigned by said channel assigning signal received by said communication unit.
 6. The video signal recording transmitter according to claim 1, wherein the video signal recording transmitter has a communication unit for receiving a channel assigning signal from another device, a channel assigning unit for assigning the channel by a user of this device, and an automatic channel switching unit for sequentially switching the channel at a time interval determined in advance, and said channel selecting control unit selects whether it is said channel assigning signal received by said communication unit, an output from said channel assigning unit, or an output of said automatic channel switching unit, and controls the operation of said second video signal compressing unit so as to selectively compress the specific channel assigned by someone.
 7. The video signal recording transmitter according to claim 1, wherein the video signal recording transmitter has a unit for receiving a zoom processing assigning signal from a monitoring device, and a zoom processing circuit for enlarging and processing a predetermined portion of an image in accordance with the zoom processing assigning signal, and the second video signal compressing processing is performed after the predetermined portion of the image is enlarged and processed on the basis of the zoom processing assigning signal.
 8. The video signal recording transmitter according to claim 1, wherein said first video signal compressing unit performs the compression-encoding processing of an MPEG2 format, and said second video signal compressing unit performs the compression-encoding processing of an MPEG4 format.
 9. A monitoring system for connecting the video signal recording transmitter according to claim 1 and a monitoring device to each other by a communication unit, and characterized in that said video signal input is an output from a photographing device.
 10. The monitoring device constituting the monitoring system according to claim 9, wherein the monitoring device has a unit for outputting a channel assigning signal for assigning the selection of a channel in the video signal recording transmitter.
 11. The monitoring device according to claim 10, wherein the monitoring device has a function for transmitting the channel assigning signal, and a function for receiving an image signal of the selected channel.
 12. A monitoring system for connecting plural camera devices and a video signal recording transmitter through a LAN, and connecting this video signal recording transmitter and a monitoring device arranged in a remote place through a communication unit, and characterized in that said camera device has a first video signal compressing unit for compressing an image pickup signal and a LAN interface, and said video signal recording transmitter has: an assigning channel extracting circuit for switching and outputting video signal inputs from said plural camera devices in time division, and extracting a channel assigned on the basis of a channel assigning signal from said monitoring device, a video signal decoding unit for decoding a compression video signal of the assigning channel from the assigning channel extracting circuit, a recording unit for recording the video signal switched and outputted from said assigning channel extracting circuit in time division to a recording medium, a second video signal compressing unit for compressing an output from said video signal decoding unit in a high compressibility in comparison with said first video signal compressing unit, and a communication unit for transmitting an output signal from the second video signal compressing unit to another device.
 13. The monitoring system according to claim 12, wherein the video signal recording transmitter has a unit for receiving a zoom processing assigning signal from the monitoring device, and a zoom processing circuit for enlarging and processing a predetermined portion of an image in accordance with the zoom processing assigning signal, and the second video signal compression processing is performed after the predetermined portion of an output image from the video signal decoding unit is enlarged and processed on the basis of the zoom processing assigning signal.
 14. A monitoring system for connecting plural camera devices and a video signal recording transmitter through a LAN, and connecting this video signal recording transmitter and a monitoring device arranged in a remote place through a communication unit, and characterized in that said camera device has a first video signal compressing unit for compressing an image pickup signal, a second video signal compressing unit for compressing said image pickup signal in a high compressibility in comparison with said first video signal compressing unit, and a LAN interface, and said video signal recording transmitter has: an assigning channel extracting circuit for switching and outputting video signal inputs from said plural camera devices in time division, and extracting a channel assigned on the basis of a channel assigning signal from said monitoring device, a recording unit for recording the video signal switched and outputted from said assigning channel extracting circuit in time division to a recording medium, and a communication unit for transmitting the second video signal compressed in the high compressibility in comparison with said first video signal compressing unit from said camera device to another device.
 15. The monitoring system according to claim 14, wherein said camera device has a unit for receiving a zoom processing assigning signal from the monitoring device, and a zoom processing circuit for enlarging and processing a predetermined portion of an image in accordance with the zoom processing assigning signal, and the second video signal compression processing is performed after the predetermined portion of an output image from the video signal decoding unit is enlarged and processed on the basis of the zoom processing assigning signal. 